Method for producing a pattern for lost pattern casting

Abstract

A fabrication method for fabricating a pattern for lost pattern casting, comprising at least one insert (10), providing at least two pattern portions (12, 14), said at least two portions being made of a material that can be eliminated, and assembling said at least two pattern portions together around at least a portion of said at least one insert in sealed manner so as to make said pattern (16).

The invention claimed is: 
     
       1. A fabrication method for fabricating a pattern for lost pattern casting, the method comprising the following steps:
 S1A) providing at least one insert; 
 S1B) providing at least two pattern portions in a solid state, said at least two pattern portions being made of a material that can be eliminated; and then 
 S2) fastening directly to each other said at least two pattern portions together around at least a portion of said at least one insert in sealed manner so as to make said pattern. 
 
     
     
       2. The fabrication method according to  claim 1 , wherein said at least one insert comprises a core configured to be eliminated after a casting step during lost pattern casting. 
     
     
       3. The fabrication method according to  claim 1 , wherein step S1B) is performed by fabricating at least one of said at least two pattern portions of the pattern by an additive method or by injection molding. 
     
     
       4. The fabrication method according to  claim 1 , wherein step S1A) is performed by fabricating said at least one insert by an additive method or by injection molding. 
     
     
       5. The fabrication method according to  claim 1 , wherein the pattern includes an airfoil. 
     
     
       6. The fabrication method according to  claim 5 , wherein, in step S1B), exactly two portions of the pattern are provided, a suction side portion including a portion of the airfoil that is situated on a suction side, and a pressure side portion including a portion of the airfoil situated on a pressure side. 
     
     
       7. The fabrication method according to  claim 1 , wherein step S2) comprises two substeps:
 S21) assembling said at least two pattern portions around said at least one portion of said at least one insert by adhesive or by welding; and 
 S22) sealing the pattern. 
 
     
     
       8. A method of fabricating a lost pattern casting, comprising:
 fabricating a pattern using the method according to  claim 1 ; 
 fabricating a shell mold using the fabricated pattern; and 
 forming a casting using the fabricated shell mold.